I need to reposition more centrally a downstairs pendant ceiling rose, but cannot gain access to the ceiling void.

I realise this means that I shall only be able to move the aperture within the two first floor joists between which the aperture presently exists, but this is fine.

Having cut my new hole in the ceiling plasterboard directly beneath one of the ceiling joists (I intend to screw the new mounting to this joist), I then have the problem of accessing the existing lighting cable above the ceiling board, pulling it up through the existing aperture and then passing it down through the new aperture.

Any advice on how this can be achieved would be appreciated. I have been advised that something called a 'mouse' is ideal for this job, but I have no idea what this may be or from where I might get one.

Hi Mike,
You might be best with a cable accessory kit you can get these which are a miniture version of the industrial type. Which are ideal for this kind of work. (but no good any heavy duty pulling/drawing of cables). If think screw fix do them about a tenner a set.
The problem you need to consider is the length of cable you have in the ceiling and if it will allow you to reposition your fitting (consider loop in method this could effect both the previous light on loop and the next light on it too), you may need to run new cables from and too these fittings, you could you a junction box but as it will not be accessible after work is complete you need to use a Maintenance Free Junction Boxes.
Also take part p of building regs in to account and BS7671.
KB

Having given further thought to the task, since I presume the lighting circuit is a loop-in system and I've got to move the light approximately four feet, it is likely that there will not be enough slack cable on one side of the loop or other to move the pendant without creating some kind of join in the loop cable. Is there a single recognised and acceptable way of doing this?

Mike P.
I would say as an electrician the most acceptable way would be to install new cables between these fitting and switches, but that would mean removing the cables currently installed. Including the ones that are in the wall to the switches as they too may now not be long enough, so becomes a bit of a headache. The easiest way may be to extend the circuits by putting joint/junction boxes in. Again BS7671 the electrical requirments known as the the regs, ask for all accessories to be accessible for inspection (which joint/junction boxes come under) But on the market you will find Maintenance Free Junction Boxes, which can be installed in area that access is restricted or non available.
Regards
KB

The more one looks into this 'project' the more fraught with problems it appears to be, not least because of the limited access holes one has to work with.

As a qualified mechanical engineer I'm not one to contravene regulations and can appreciate the requirement that all electrical junctions should be available for inspection. I always feel that junctions are the circuits weak points and the less of these the better.

Without seeking any comment from you, I assume therefore that the maintenance free junction boxes contravene current regulations. There is also the problem of inserting these into the ceiling space through holes that are quite small.

You can use maintenance free junction boxes. Main problem where there is no access is that sometimes screws due to vibration can work lose the maintenance free have a spring clip arrangement. There is also soldering and crimping options.
I have never managed to get a mouse or rat to help with cables but I have used a cat who did take a string through the hollow section of a cherry picker for me to then pull in new cable.
Caused quite a laugh when I put in time sheet for the cat!
My daughter did have rats but not sure I would want them lose in my ceiling space.
I have many times used the lid from trunking or bits of conduit sometimes even leaving in place.
Multi holes in plaster board and loops of wire to catch cables are often used but although you may persevere as DIY when time is money often holes in plaster board is only senseable way.
There is no magic answer. All so often there are cross pieces in the way. Camera with flash works well to see what is going on. Or phone camera it can see where you can't.
Eric

I'm leaning towards avoiding extra cable joints and hoping that I can feed an extra length of lighting cable into the new hole and push it in the general direction of the original hole. I have chipboard flooring upstairs, so the void between the two rafters should have reasonably smooth sides, provided I don't encounter any unforeseen obstacles. Should be able to grab it as it passes over the original hole.

The plan is to replace the original lighting rose with a junction box (yes, I know it will be surface mounted and a possible eyesore, but this operation is a compromise). I'll then install a new lighting rose at the desired location under one of the two ceiling joists.

Can be a frustrating a process feeding cables through ceiling voids from below, using the method you are going to try is pot luck.
Not knocking it, I to would give it a try and hope I hit the Jackpot straight away.
The problem is there could be anything within them voids, other cables, pipes, nogins, debris from other work carried out. To name a few!
As Eric has said there are other jointing methods, but they will need some specialist tools. That is why I suggest the maintance free joint box, it complys to the regs and is allowed within areas that have limited or no access.
I'd cut a hole in the ceiling to make this joint where the light is currently located, then patch it up after you have carried out the installation of circuit. surely better than having a joint box fixed to ceiling
If you need help with patch, I can do that.
KB

I was doing some wiring in a house a couple of years ago and the owner trepanned holes in the ceiling wherever they were needed. He then stuck the circular cut-outs back in place with no-nails adhesive. With a bit of filling you could not tell where the holes had been. Of course, this only works if the ceiling has not been artexed. The holes were about 100mm in diameter. This allowed us to drill the joists quite easily.
Also, I was looking at a kit in B&Q the other day which you used with a router to cut holes in a chip board floor. You then replaced the circle of chip board using a circular plastic frame to support it, and it all sat flush to the floor when the job was finished.

I'm going to thread a new cable to the new location using something similar to an electrician's 'mouse', i.e. a thin reel of flat flexible steel with a sprung ball end. The new pendant fixture has its own securing bracket which will be fixed to one of the joists either side of the existing rose.

My remaining question concerns what to do about the existing rose. I don't intend closing up the existing ceiling hole and am not averse to the sight of a redundant rose or some form of circular, closed containment box on the ceiling. It is a loop-in lighting system. I've spoken to MK Electrics, who simply suggest leaving the existing rose connected as it is and taking the feed cable back up through it into the void and across to the new location. I may have to consider putting some white silicone sealer in the cover's hole.

Before this I had planned to dispense with the existing rose, re-connect the loop-in wires in junction box style using four individual plastic-coated wire connectors (i.e. leaving the connections accessible to meet regulations) and hide the connectors behind a circular rear accessed box with a closed cover.

My problem is that I cannot identify such a box to replace the rose. Can any one suggest something suitable? If not I shall be resigned to following MK's solution.

I'm going to thread a new cable to the new location using something similar to an electrician's 'mouse', i.e. a thin reel of flat flexible steel with a sprung ball end. The new pendant fixture has its own securing bracket which will be fixed to one of the joists either side of the existing rose.

My remaining question concerns what to do about the existing rose. I don't intend closing up the existing ceiling hole and am not averse to the sight of a redundant rose or some form of circular, closed containment box on the ceiling. It is a loop-in lighting system. I've spoken to MK Electrics, who simply suggest leaving the existing rose connected as it is and taking the feed cable back up through it into the void and across to the new location. I may have to consider putting some white silicone sealer in the cover's hole.

Before this I had planned to dispense with the existing rose, re-connect the loop-in wires in junction box style using four individual plastic-coated wire connectors (i.e. leaving the connections accessible to meet regulations) and hide the connectors behind a circular rear accessed box with a closed cover.

My problem is that I cannot identify such a box to replace the rose. Can any one suggest something suitable? If not I shall be resigned to following MK's solution.

Hi,
It sounds what you are suggesting is very much like what MK have mentioned anyway, not what i'd do. So don't think I can comment any further, I have already suggest what I thought was best solution.
KB